Heterogeneous nuclear ribonucleoprotein K (hnRNP K) belongs to a family of RNA binding multiprotein complexes (hnRNP proteins) that facilitate pre-mRNA processing and transport of mRNA from the nucleus to cytoplasm. hnRNP K contains three unique structural motifs termed KH domains that bind poly(C) DNA and RNA sequences. Intricate architecture enables hnRNP K to facilitate mRNA biosynthesis, transcriptional regulation, and signal transduction. Research studies have shown that cytoplasmic hnRNP K expression is increased in oral squamous cell carcinoma and pancreatic cancer, and may be a potential prognostic factor. hnRNP K coordinates with p53 to regulate its target gene transcription in response to DNA damage. Proteasome degradation of hnRNP K is mediated by E3 ligase MDM2. The interaction between hnRNP K and c-Src leads to hnRNP K phosphorylation, which allows for hnRNP K activation of silenced mRNA translation.